Photo Illustration by The Daily Beast

The Supreme Court today held that the federal government can’t force states to ban sports betting. In the short term, it’s a big win for sports betting operations that can now expand a hundredfold. In the long term, the decision could affect everything from “sanctuary cities” to environmental law.

The short-term consequences are immediate and immense. The Professional and Amateur Sports Protection Act (PAPSA), which required states to maintain their historic bans, is history. Now every state—including New Jersey, which had led this fight—can now choose to legalize sports betting, which currently is only fully legal in Nevada.

Casino magnates like Sheldon Adelson and Steve Wynn, both prominent Trump supporters, may have just lost their monopolies—or they may expand into new and far larger markets.

And the big sports associations, led by the NCAA, suffered a significant setback in trying to sever their “legitimate” operations from the taint of gambling.

But the real reason the new case, Murphy v. NCAA, is so important is federalism. For much of the 20th century, federalism was a weak doctrine. Sure, the states were semi-autonomous on paper, but in practice, the federal government ruled supreme. Civil rights laws, the administrative state, social security—all of these were made possible by the Supreme Court allowing the federal government to expand.

The opposition was minimal. From the 1860s to the 1960s, “states’ rights” was practically a code word for slavery, Jim Crow, and the Confederacy. Meanwhile, the world, and the United States, was growing smaller, thanks to jet travel, telecommunications, and interstate highways. Practically all commerce became “interstate commerce,” which enabled the federal government to regulate it.

In the last few decades, though, conservatives have turned back the tide. Laws which were once taken for granted are now rolled back as federal overreach. The Tenth Amendment, once a constitutional relic, became the cornerstone of a legal philosophy limiting federal power. “States’ rights” is for real.

And it’s the basis of Murphy. Joined by Justices Kagan and Breyer, the Court’s conservatives held that the federal government can’t tell states that they have to ban sports betting because of a judicial principle known as “anti-commandeering.” Justice Alito’s opinion for the Court said that PAPSA was like having Congress sit in state legislatures, ordering legislators what to do.

“Laws which were once taken for granted are now rolled back as federal overreach. The Tenth Amendment, once a constitutional relic, became the cornerstone of a legal philosophy limiting federal power.”

Now, Congress can still ban sports betting nationwide and make it a federal offense. But what Congress cannot do is tell the states what to ban and what not to ban.

Just think about that for a moment.

Federalism is generally a conservative value. For example, the “Federalist Society” is an ultra-conservative network of lawyers, law professors, and judges that is largely responsible for the Trump administration’s unprecedented packing of the federal judiciary with hard-right conservatives. Federalism was also behind Scott Pruitt’s crusade against the EPA, before he was appointed to lead it.

And taken to extremes, federalism could invalidate whole swaths of the contemporary administrative state. Most environmental and civil rights laws, for example, rely on the commerce clause. But if “regulating interstate commerce” is understood narrowly rather than broadly, the commerce clause may not apply to, say, a wetland in Arkansas or a lake in North Dakota.

But Murphy shows how federalism can lead to non-conservative results as well. Of course, in the short term, it allows more gambling, which will alienate not just the NCAA but Christian conservatives as well. The CEO of betting infrastructure provider Sportradar, which stands to win big under the new regime, told The Daily Beast that Murphy is a “landmark decision” and “seismic shift.”

More importantly, though, if Congress can’t tell states to ban sports betting, how can the Trump administration threaten to withhold funds to states or cities who have chosen to become “sanctuary cities” and not share information with federal immigration agents? How can the Sessions-led Justice Department restart the drug war, penalizing states for legalizing marijuana?

We’ve already seen federalist logic at work in the immigration context. Last year, for example, the Ninth Circuit sided with the state of Washington against Trump’s travel ban, in part on federalism grounds, and a district court ruled against Trump’s attempt to withhold money from sanctuary cities, also on federalism grounds.

And federalism has, in recent years, contributed to the line of cases guaranteeing the right to marriage for gay as well as straight people. In 2012, for example, the Defense of Marriage Act was struck down on the circuit court level because marriage was a matter for the states, not the federal government.

Cases like these are likely to increase in the coming years. In general, states have turned into defenders of progressive values against the Trump administration, rather than defenders of conservative values against the Obama administration.